Gate latch

ABSTRACT

A selectively operable gate latch having a pair of latch arms which are independently movable between raised and extended positions. The latch is normally secured to the gatepost, and the arms are spaced apart to receive the gate when both are extended. One long and two short locking pins are selectively utilized to lock either or both of the arms in either position, in order to provide four basic latch configurations. To lock the gate closed, the long pin is inserted through transverse openings in the arms that are aligned when both arms are extended. To provide a gate stop or gate bump to prevent opening and closing of the gate except on one side, the two short pins are used to lock the arms in opposite positions (one arm raised and the other extended). The fourth basic configuration permits the gate to swing freely, thus both arms are locked in their raised positions either by the long pin or by both short pins.

United States Patent [191 Maze [ Apr. 23, 1974 GATE LATCH Perry V. Maze, 704 Morton, Falls City, Nebr. 68355 [22] Filed: June 23, 1972 [21] Appl. No.: 265,670

[76] Inventor:

[52] U.S. Cl 292/44, 292/207, 292/238 [51] Int. Cl. E05c 3/02 [58] Field of Search 292/44, 45, 54, 207, 299

[56] References Cited UNITED STATES PATENTS 2,510,178 6/1950 James 292/44 1,950,251 3/1934 Kulefsky.... 292/207 X Williams 292/54 Primary ExaminerRichard E. Moore 57 1 ABSTRACT A selectively operable gate latch having a pair of latch arms which are independently movable between raised and extended positions. The latch is normally secured to the gatepost, and the arms are spaced apart to receive the gate when both are extended. One long and two short locking pins are selectively utilized to lock either or both of the arms in either position, in order to provide four basic latch configurations. To lock the gate closed, the long pin is inserted through transverse openings in the arms that are aligned when both arms are extended. To provide a gate stop or gate bump to' prevent opening and closing of the gate except on one side, the two short pins are used to lock the arms in opposite positions (one arm raised and the other extended). The fourth basic configuration permits the gate to swing freely, thus both arms are locked in their raised positionseither by the long pin or by both short pins.

6 Claims, 4 Drawing Figures GATE LATCH This invention relates to improvements in gate latches or looks and, more specifically, to a gate latch particularly adapted for heavy-duty applications and which has a number of operational configurations.

The gate locks presently used by farmers and ranchers are oftentimes very crude and provide little resistance to breaking and entering. Such locks may be no more than a piece of wire wrapped around the gatepost and adjacent end of the gate, and may or may not be secured by a padlock. Obviously, besides constituting little deterrent to breaking and entering, a lock of this type is difficult and time consuming to release or secure.

Furthermore, in high security installations such as encountered in governmental and industrial applications the securing of gates is also a problem. A gate latch in such applications must have the capability of withstanding severe abuse in normal usage, as well as high resistance to breaking and entering. Manifestly, heavy gate structures are oftentimes employed thereby requiring that latches and locks have a mechanical strength consistent with the strength of the gate and fence structure.

It is, therefore, the primary object of the present invention to provide a heavy-duty gate lock for applications where a deterrent to breaking and entering is of prime importance and where the lock will be subject to abusive treatment in normal usage.

As a corollary to the foregoing object, it is an important aim of this invention to provide a gate lock as aforesaid which combines high mechanical strength with ease of operation to facilitate both the release and the locking of the gate.

A further and important object of the invention is to provide a gate lock as aforesaid having a number of operational configurations that enable the lock to serve as a gate stop or gate bump as well as a conventional latch.

Still another important object of the invention is to provide a gate lock as aforesaid having a pair of independently movable latch arms that may be selectively locked in either an inoperative or an operative position in order to present the mentioned configurations.

Yet another important object of the invention is to provide a gate lock with the aforesaid operational configurations, including four basic configurations as follows: both latch arms locked in their operative positions to lock the gate closed, the arms locked in opposite positions to provide a gate stop that prevents opening and closing of the gate except on one side. and both arms locked in their inoperative positions to permit the gate to swing freely. 1

Additionally, it is a specific and important object of the invention to provide such a lock in which selectively utilized locking pins are employed which are engageable with the arms to enable the user to select the operational configuration desired.

In the drawing: I

FIG. 1 is a top plan view of the latch or lock of the present invention, showing the same secured to a gatepost with the latch arms illustrated in their extended positions in full lines;

FIG. 2 is a side elevational view of the latch of FIG. 1, the post being removed from the illustration;

FIG. 3 is a front elevational view of the latch of FIG. 1, the latch arms being illustrated in their raised positions in broken lines; and

FIG. 4 is a view similar to FIG. 3 on a reduced scale, illustrating the use of two short locking pins rather than the single, long locking pin.

The latch of the present invention comprises a T- shaped supporting frame broadly denoted by the numeral 10 and best seen by comparing FIGS. 1 and 2. The frame 10 is shown in FIG. 1 secured to a wooden gatepost 12 by two pieces of strap iron 14, each of which partially surrounds the post 12. Although not seen in the figures, the straps 14 are provided with spaced holes along their lengths through which nails may be driven to securely attach the straps to the wooden post 12. Furthermore, as a primary means of attachment to the post 12, the frame 10 has an upright leg 16 provided with a pair of holes 18 (FIG. 3) for re ceiving bolts (not shown) that extend completely through the post 12.

A horizontally extending U-shaped component 20 forms the top of the T-shaped frame 10 and supports a pivot pin 22 that mounts a pair of latch arms '24 for swinging movement between raised and extended positions. More particularly, it may be noted in FIG. 1 that the component 20 includes a horizontal bight 26 provided with a pair of forwardly extending wings 28 at its opposed ends. The pivot pin 22 spans the wings 28 in parallelism with the bight- 26 and supports the inner ends of the two arms 24, transverse openings (not shown) being provided in the arms 24 for receiving the pin 22 extending therethrough. Accordingly, each of the arms 24 is free to swing about the pin 22 between the extended position illustrated in full lines in the figures, and an inoperative, raised position illustrated in broken lines. For structural strength, the bight portion 26 of the component 20 comprises an angle member presenting upright and horizontally disposed plates 30 and-32 respectively, the arms 24 resting against the plate 30 in their raised positions and being supported on the horizontal plate 32 in their extended positions. Additional reinforcement to be discussed is employed, however, to securely hold the arms 24 against lateral movement in their extended positions, thus the arms 24 do not bear directly on the plate 32 as may be seen in FIG. 3. I

A pair of angle pieces 34 are welded to the plates 30 and 32 to form a pair of U-shaped members 36 that receive respective arms 24 when the latter are extended, as is clear in FIG. 3. For high strength, cold rolled steel is preferred for the arms 24 and the pivot pin 22. Since each arm 24 is effectively captured within the associated U-shaped member 36 when the arm is extended, it may be appreciated that the latch is capable of resisting a very high lateral impact. Note that each arm 24 is located just inside the adjacent wing 28 which is integral with the angle piece 34 that cooperates with the wing 28 and underlying portion of the plate 32 to present the U-shaped member 36.

A locking pin 38 of greater length than the distance between the wings 28 is shown in FIGS. 1-3 spanning the wings 28 and projecting laterally outwardly therefrom. The locking pin 38 will be referred to hereinafter as the long pin since it is common to the two arms 24 and is employedto simultaneously lock the arms in either the raised or extended position. Note in FIG. 1 that a transverse opening 40 is provided in each arm 24 for the purpose of receiving the pin 38 when the arm is in its extended position. These two openings 40 are aligned when both of the arms 24 are extended, and similar openings are provided in the wings 28 and the angle pieces 34 to permit the pin 38 to be inserted from either side Completely through the aligned openings in the various parts until it reaches the position illustrated. Withdrawal of the pin .38 is prevented by a suitable retainer illustrated herein as a hairpin clip 42 extending through a transverse hole 44 adjacent the end of the pin. A head 46 is provided on the opposite side of the pin 38 and is secured to the frame by a chain 48 to prevent loss of the pin 38 when it is removed.

Two additional chains 50 are attached to the heads of two locking pins 52 of considerably shorter length than the long pin 38. FIG. 4 illustrates the use of the two short pins 52 which permit the latch arms 24 to be independently locked in either position. Either of the pins 52 may be inserted through the aligned openings in one of the wings 28 and the adjacent arm 24 and angle piece 34, and retained by a hairpin clip 54.

OPERATION The frame 10 is attached to the gatepost 12 by bolts through the holes 18 in leg 16, and by the straps 14 that are secured to the input backplate 30 of the horizontal frame component 20. The construction of the attaching means may be changed as necessary to accommodate the particular gatepost construction and configuration, the wooden type post being shown herein simply for purposes of illustration. Furthermore, the latching device could be secured to the gate (not shown) rather than the stationary post 12, but attachment to the post is normally preferred.

The latching device has four basic operational configurations, the desired configuration being selected through the use of the appropriate locking pin or pins. Besides preventing loss, the chains 48 and 50 attached to the heads of the locking pins assure that these pins are always conveniently available at the latching device for the selective use of the operator.

It will now be assumed that it is desired to lock the gate in the closed position. This is readily accomplished by shutting the gate and swinging the latch arms 24 to their extended positions receiving the gate therebetween. The long pin 38 is inserted along the common axis defined by the transverse openings40 in the arms 24, and retained by the hairpin clip 42. Alternatively, for a security look, a padlock 56 may be used in place of the clip 42. For high security, the pin 38 may be case hardened to prevent cutting by a hacksaw or file.

The second basic operational configuration employs the latching device as a gate stop or gate bump to prevent opening and closing movement of the gate except on one side. This is shown in FIG. 1 considering the broken line illustration of the right-hand latch arm 24. When the long pin 38 is now inserted, it looks the left arm 24 in the extended position but locks the right arm 24 in the raised position. The locking of the right arm 24 is accomplished by virtue of the spacing between the axis of the pivot' pin 22 and the outer surface of the locking pin 38. This spacing is approximately equal to the diameter of the arm 24 so that significant movement thereof is precluded since the arm is effectively captured between the locking pin 38 and the upright backplate 30.

It is preferred, however, to utilize the two short pins 52 when the latch is employed as a gate stop. This permits the raised arm to be left unlocked by simply using one of the pins 52 to lock the extended arm. Use of the two short pins 52 is illustrated in FIG. 4 and shows the third operational configuration of the latch which is identical to the second configuration just described, ex-

cept that now the left arm 24' is raised and the right arm- 24 is extended. Manifestly, selection of the desired configuration will depend upon the side from which it is desired to open and close the gate.

The fourth basic configuration is illustrated by the broken lines in FIG. 3. Both latch arms 24 are locked in their inoperative, raised positions by the long locking pin 38. Alternatively, both of the short pins 52 may be utilized, as is the case with the fully locked configuration with both arms extended. I

As mentioned hereinabove, very high mechanical strength is provided particularly when the arms 24 are extended, which is the condition where high strength is of importance. It may be appreciated that a lateral force applied to either arm 24 by the gate itself in normal usage or by an intruder is transmitted to the rigid frame 10. Besides the pivot pin 22 and the selected locking pin, the force is received by the U shaped member 36 which reinforces the inner endportion of the extended arm 24. Furthermore, the dual pins and the member 36 also provide reinforcement against a vertical impact on the arm 24 that might be applied by an intruder. According, the present invention serves as a deterrent to breaking and entering without sacrificing ease of operation, and has the multiple configuration capability set forth above to provide a latching device of great versatility.

From the foregoing, it will be seen that this invention is one well' adapted to attain all of the ends'and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.

It will'be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown' in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

l. A selectively operable latching device for locking a movable gate member to an adjacent post member in a closed position and for limiting opening and closing movement of the gate member, said device comprising:

a pair of latch arms;

a support adapted to be secured to one of said members and having means mounting each of said arms for independent movement between an inoperative position and an extended, latching position,

said arms being spaced apart for receiving the other of said members when both of said arms are in said extended positions; and

lock means removably engageable'with said arms and said support for selectively locking one or both of said arms with respect to said support in said extended position, or out thereof, 4

whereby when both arms are locked in their extended positions receiving said other member therebetween, the gate member is locked closed, and when one arm is locked in its extended position and the other arm is in its inoperative position, the one extended arm presents a gate stop for preventing opening and closing movement of the gate member except on one side,

said lock means including a pair of selectively utilized locking elements, one of said elements being common to said arms and removably engageable with both of the latter in their extended positions, the other of said elements being removably engageable with either individual arm in its extended position.

2. The device as claimed in claim 1, wherein said lock means includes, in addition to the element common to said arms, a pair of selectively utilizable locking elements for the respective arms, each of said elements being removably engageable with an individual arm to independently lock same in its extended position.

3. A selectively operable latching device for locking a movable gate member to an adjacent post member in a closed position and for limiting opening and closing movement of the gate member, said device comprising:

a pair of latch arms;

a support adapted to be secured to one of said members and having means mounting each of said arms for independent movement between an inoperative position and an extended, latching position,

said arms being spaced apart for receiving the other of said members when both of said arms are in said extended positions,

lock means engageable with said arms for selectively locking one or both of said arms in said extended position, whereby when both arms are locked in their extended positions receiving said other member therebetween, the gate member is locked closed, and when one arm is locked in its extended position and the other arm is in its inoperative position, the one extended arm presents a gate stop for preventing opening and closing movement of the gate member except on one side,

each of said arms having a pair of opposed, inner and outer ends, said mounting means including a pivot pin supporting the inner ends of said arms for swinging movement of each arm between said inoperative and extended positions,

said lock means including a removable locking pin common to said arms, and a structure on said support for receiving said locking pin in a disposition generally parallel to said pivot pin and with the locking pin bridging both of said arms and engaging each arm in either its inoperative or extended position, whereby either or both of said arms may be locked in the inoperative position as well as the extended position.

4. A selectively operable latching device for locking a movable gate member to an adjacent post member in a closed position and for limiting opening and closing movement of the gate member, said device comprising:

a pair of latch arms;

a support adapted to be secured to one of said members and having means mounting each of said arms for independent movement between an inoperative position and an extended, latching position,

said arms being spaced apart for receiving the other of said members when both of said arms are in said extended positions,

lock means engageable with said arms for selectively locking one or both of said arms in said extended position, whereby when both arms are locked in their extended positions receiving said other member therebetween, the gate member is locked closed, and when one arm is locked in its extended position and the other arm is in its inoperative position, the one extended arm presents a gate stop for preventing opening and closing movement of the gate member except on one side,

each of said arms having a pair of opposed, inner and outer ends, said mounting means including a pivot pin supporting the inner ends of said arms for swinging movement of each arm between said inoperative and extended positions,

said lock means including first and second selectively utilized locking pins, said first pin being common to said arms and of greater length than the space therebetween, said second pin being relatively short, and structure on said support for receiving the selected locking pin in a disposition generally parallel to said pivot pin and with the selected locking pin engaging both of said arms in either inoperative or extended positions if said first pin is selected, or either individual arm in its inoperative or extended position if said second pin is selected, whereby said first locking pin is utilized to lock both arms in either position thereof and said second locking pin is utilized to lock either arm individually in either of its positions.

5. A selectively operable latching device for locking 40 a movable gate member to an adjacent post member in a closed position and for limiting opening and closing movement of the gate member, said device comprising:

a pair of latch arms,

a support adapted to be secured to one of said members and having means mounting each of said arms for independent movement between an inoperative position and an extended, latching position,

said arms being spaced apart from receiving the other of said members when both of said arms are in said extended positions,

lock means engageable with said arms for selectively locking one or both of said arms in said extended position, whereby when both arms are locked in theirextended positions receiving said other member therebetween, the gate member is locked closed, and when one arm is locked in its extended position and the other arm is in its inoperative position, the one extended arm presents a gate stop for preventing opening and closing movement of the gate member except on one side,

said support including a normally upright leg for attachment to said one member and provided with a generally horizontally extending component of U- shaped configuration,

said component presenting a bight and a pair of opposed wings,

7 said mounting means including a pivot pin spanning said wings and carried by the latter, each of said arms having a pair of opposed, inner and outer ends,

said pivot pin supporting the inner ends of said arms adjacent respective wings inside the latter for tachment to said one member and provided with a swinging movement of said arms between said ingenerally horizontally extending component of U- operative and extended positions, shaped configuration,

each of said arms having a transverse opening therein said component presenting a bight and a pair of opadjacent the inner end thereof and closely spaced 10 posed wings, from said pivot pin, and said openings defining a said mounting means including a pivot pin spanning common axis generally parallel to said pivot pin said wings and carried by the latter, when said arms are in their extended positions, each of said arms having a pair of opposed, inner and said lock means including first and second selectively outer ends,

utilized locking pins receivable within the opening 5 said pivot pin supporting the inner ends of said arms in each arm, said first pin being common to said adjacent respective wings inside the latter for arms and of greater length than the space therebeswinging movement of said arms between said intween, said second pin being relatively short, and operative and extended positions, parts between said arms rigid with said component each of said arms having a transverse opening therein and cooperating with said wings for receiving the adjacent the inner end thereof and closely spaced selected locking pin in a disposition coaxial with from said pivot pin,'and said openings defining a said common axis for engagement of the selected common axis generally parallel to said pivot pin locking pin with both of said arms in either operawhen said arms are in their extended positions, tive or extended positions if said first pin is sesaid lock means including first and second selectively lected, or either individual arm in its operative or utilized locking pins receivable within the opening extended'position if said second pin is selected. 6. A selectively operable latching device for locking position and the other arm is in its inoperative position, the one extended arm presents a gate stop for preventing opening and closing movement of the gate member except on one side,

said support including a normally upright leg for at:

in each arm, said first pin being common to said arms and of greater length than the space therebetween, said second pin being relatively short, and parts between said arms rigid with said component and cooperating with said wings for receiving the selected locking pin in a disposition coaxial with said common axis for engagement of the selected locking pin with both of said arms in either operative or extended positions if said first pin is selected, or either individual arm in its operative or extended position if said second pin is selected, said component including a generally horizontally exa movable gate member to an adjacent post member in a closed position and for limiting opening and closing movement of the gate member, said device comprising:

a pair of latch arms;

a support adapted to be secured to one of said members and having means mounting each of said arms for independent movement between an inoperative position and an extended, latching position,

said arms being spaced apart for receiving the other of said members when both of said arms are in said extended positions; and v lock means engageable' with said arms for selectively 40 locking one or both of said arms in said extended position, whereby when both arms are locked in their extended positions receiving said other member therebetween, the gate member is locked closed, and when one arm is locked in its extended upright and horizontal plates defining substantially the limits of movement of said arms between said inoperative and extended positions respectively, said parts and adjacent wings being integral with members receiving respective arms.

tending angle member presenting a pair of integral,-

said horizontal plate to present a pair of U-shaped 

1. A selectively operable latching device for locking a movable gate member to an adjacent post member in a closed position and for limiting opening and closing movement of the gate member, said device comprising: a pair of latch arms; a support adapted to be secured to one of said members and having means mounting each of said arms for independent movement between an inoperative position and an extended, latching position, said arms being spaced apart for receiving the other of said members when both of said arms are in said extended positions; and lock means removably engageable with said arms and said support for selectively locking one or both of said arms with respect to said support in said extended position, or out thereof, whereby when both arms are locked in their extended positions receiving said other member therebetween, the gate member is locked closed, and when one arm is locked in its extended position and the other arm is in its inoperative position, the one extended arm presents a gate stop for preventing opening and closing movement of the gate member except on one side, said lock means including a pair of selectively utilized locking elements, one of said elements being common to said arms and removably engageable with both of the latter in their extended positions, the other of said elements being removably engageable with either individual arm in its extended position.
 2. The device as claimed in claim 1, wherein said lock means includes, in addition to the element common to said arms, a pair of selectively utilizable locking elements for the respective arms, each of said elements being removably engageable with an individual arm to independently lock same in its extended position.
 3. A selectively operable latching device for locking a movable gate member to an adjacent post member in a closed position and for limiting opening and closing movement of the gate member, said device comprisIng: a pair of latch arms; a support adapted to be secured to one of said members and having means mounting each of said arms for independent movement between an inoperative position and an extended, latching position, said arms being spaced apart for receiving the other of said members when both of said arms are in said extended positions, lock means engageable with said arms for selectively locking one or both of said arms in said extended position, whereby when both arms are locked in their extended positions receiving said other member therebetween, the gate member is locked closed, and when one arm is locked in its extended position and the other arm is in its inoperative position, the one extended arm presents a gate stop for preventing opening and closing movement of the gate member except on one side, each of said arms having a pair of opposed, inner and outer ends, said mounting means including a pivot pin supporting the inner ends of said arms for swinging movement of each arm between said inoperative and extended positions, said lock means including a removable locking pin common to said arms, and a structure on said support for receiving said locking pin in a disposition generally parallel to said pivot pin and with the locking pin bridging both of said arms and engaging each arm in either its inoperative or extended position, whereby either or both of said arms may be locked in the inoperative position as well as the extended position.
 4. A selectively operable latching device for locking a movable gate member to an adjacent post member in a closed position and for limiting opening and closing movement of the gate member, said device comprising: a pair of latch arms; a support adapted to be secured to one of said members and having means mounting each of said arms for independent movement between an inoperative position and an extended, latching position, said arms being spaced apart for receiving the other of said members when both of said arms are in said extended positions, lock means engageable with said arms for selectively locking one or both of said arms in said extended position, whereby when both arms are locked in their extended positions receiving said other member therebetween, the gate member is locked closed, and when one arm is locked in its extended position and the other arm is in its inoperative position, the one extended arm presents a gate stop for preventing opening and closing movement of the gate member except on one side, each of said arms having a pair of opposed, inner and outer ends, said mounting means including a pivot pin supporting the inner ends of said arms for swinging movement of each arm between said inoperative and extended positions, said lock means including first and second selectively utilized locking pins, said first pin being common to said arms and of greater length than the space therebetween, said second pin being relatively short, and structure on said support for receiving the selected locking pin in a disposition generally parallel to said pivot pin and with the selected locking pin engaging both of said arms in either inoperative or extended positions if said first pin is selected, or either individual arm in its inoperative or extended position if said second pin is selected, whereby said first locking pin is utilized to lock both arms in either position thereof and said second locking pin is utilized to lock either arm individually in either of its positions.
 5. A selectively operable latching device for locking a movable gate member to an adjacent post member in a closed position and for limiting opening and closing movement of the gate member, said device comprising: a pair of latch arms, a support adapted to be secured to one of said members and having means mounting each of said arms for independent movement between an inoperative position and an extended, latching position, said arms being spaced apart from receiving thE other of said members when both of said arms are in said extended positions, lock means engageable with said arms for selectively locking one or both of said arms in said extended position, whereby when both arms are locked in their extended positions receiving said other member therebetween, the gate member is locked closed, and when one arm is locked in its extended position and the other arm is in its inoperative position, the one extended arm presents a gate stop for preventing opening and closing movement of the gate member except on one side, said support including a normally upright leg for attachment to said one member and provided with a generally horizontally extending component of U-shaped configuration, said component presenting a bight and a pair of opposed wings, said mounting means including a pivot pin spanning said wings and carried by the latter, each of said arms having a pair of opposed, inner and outer ends, said pivot pin supporting the inner ends of said arms adjacent respective wings inside the latter for swinging movement of said arms between said inoperative and extended positions, each of said arms having a transverse opening therein adjacent the inner end thereof and closely spaced from said pivot pin, and said openings defining a common axis generally parallel to said pivot pin when said arms are in their extended positions, said lock means including first and second selectively utilized locking pins receivable within the opening in each arm, said first pin being common to said arms and of greater length than the space therebetween, said second pin being relatively short, and parts between said arms rigid with said component and cooperating with said wings for receiving the selected locking pin in a disposition coaxial with said common axis for engagement of the selected locking pin with both of said arms in either operative or extended positions if said first pin is selected, or either individual arm in its operative or extended position if said second pin is selected.
 6. A selectively operable latching device for locking a movable gate member to an adjacent post member in a closed position and for limiting opening and closing movement of the gate member, said device comprising: a pair of latch arms; a support adapted to be secured to one of said members and having means mounting each of said arms for independent movement between an inoperative position and an extended, latching position, said arms being spaced apart for receiving the other of said members when both of said arms are in said extended positions; and lock means engageable with said arms for selectively locking one or both of said arms in said extended position, whereby when both arms are locked in their extended positions receiving said other member therebetween, the gate member is locked closed, and when one arm is locked in its extended position and the other arm is in its inoperative position, the one extended arm presents a gate stop for preventing opening and closing movement of the gate member except on one side, said support including a normally upright leg for attachment to said one member and provided with a generally horizontally extending component of U-shaped configuration, said component presenting a bight and a pair of opposed wings, said mounting means including a pivot pin spanning said wings and carried by the latter, each of said arms having a pair of opposed, inner and outer ends, said pivot pin supporting the inner ends of said arms adjacent respective wings inside the latter for swinging movement of said arms between said inoperative and extended positions, each of said arms having a transverse opening therein adjacent the inner end thereof and closely spaced from said pivot pin, and said openings defining a common axis generally parallel to said pivot pin when said arms are in their extended positions, said lock means including first and second selectively utilized locking pins receivable within the opening in each arm, said first pin being common to said arms and of greater length than the space therebetween, said second pin being relatively short, and parts between said arms rigid with said component and cooperating with said wings for receiving the selected locking pin in a disposition coaxial with said common axis for engagement of the selected locking pin with both of said arms in either operative or extended positions if said first pin is selected, or either individual arm in its operative or extended position if said second pin is selected, said component including a generally horizontally extending angle member presenting a pair of integral, upright and horizontal plates defining substantially the limits of movement of said arms between said inoperative and extended positions respectively, said parts and adjacent wings being integral with said horizontal plate to present a pair of U-shaped members receiving respective arms. 